The analog bandwidth of a real-time oscilloscope is the highest frequency of an applied input signal that the oscilloscope is able to faithfully capture. Conventional real-time oscilloscopes typically use a digitizing architecture, in which the applied input signal is converted from the analog domain into digital data by an analog-to-digital converter (ADC). The digital data is then processed to display a waveform corresponding to the input signal on a display, and to extract desired information about the input signal.
Due to technological limitations of the ADC and related analog circuitry, the bandwidth of a real-time oscilloscope channel is limited. For example, a conventional oscilloscope may include four channels, each of which has a limited bandwidth of 0 (DC) to about 32 GHz. Therefore, an input signal having a bandwidth greater than 32 GHz cannot be faithfully captured by a single oscilloscope channel. One approach to overcome this limitation is to divide the input signal into multiple sub-signals each having a bandwidth less than the bandwidth of the available oscilloscope channel, followed by reconstruction after each of the sub-signals is digitized and passed through a corresponding oscilloscope channel, which may be referred to as frequency domain interleaving. However, interleaving processes may cause various, undesirable signal impairments.
As technology for modern electronics advances, there exists an increasing need to accurately and efficiently digitize input signals having frequency components covering more than the available bandwidth of an oscilloscope channel.